Gas burner control



Jan. 17 1956 c. A. COBB 2,731,080

GAS BURNER CONTROL Filed Feb. 18, 1952 -2 Sheets-Sheet l IN VEN TOR.

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Jan. 17, 1956 c. A. coBB 2,731,080

GAS BURNER CONTROL Filed Feb. 18, 1952 2 Sheets-Sheet 2 IN VEN TOR.

United States Patent O GAS BURNER CNTROL Clifton A. Cobb, Goshen, Ind., assignor to Penn Controls, Inc., Goshen, Ind., a corporation of indiana Application February 18, 1952, Serial No. 272,641

' 11 claims. (ci. 15s-13s) This invention relates to a gas burner control including a safety and operational sequence valve which functions as a safety control valve, a main gas control valve, a bypass gas control valve and a flashing gas control valve.

One object of the invention is to provide a relatively simple valve structure and a system of gas supply valve, pilot burners associated with a main burner and a constantly burning top pilot burner for automatically igniting an oven burner or broiler burner from the top pilot burner of a stove or gas range, thus providing single point ignition for all the burners of a gas range, the valve structure being designed for automatically furnishing gas to flash burners and cutting it oif thereto, and for opening a main valve by temperature responsive mechanism so that the valve can reclose to perform a safety function in case of pilot flame or gas supply failure, the arrangement being such that a standby llame is maintained at the main burner during a cooling off cycle of the temperature responsive mechanism in order to relight the main burner if the gas supply valve is turned on again during the cooling cycle, the completion of the cooling m'cle causing the parts of the valve to revert to the proper `position for automatic recycling thereof.

Another object is to provide a safety and operational sequence valve including a main valve seat, a main valve supported by a diaphragm and normally seated thereagainst, a bypass valving arrangement for ash burners and a thermal control for the main valve which has a gas bypass around the main valve for maintaining a small standby ame at the main burner itself during a cooling cycle of the valve, thus eliminating a separate standby pilot burner.

A further object is to provide in connection with a gas supply system means of the character disclosed for supplying gas to the main valve which will cause operation thereof in such manner as to first supply gas to flash burners for propagating flame from a continuously burning pilot burner to the pilot burner for the main burner and then turn on the gas for the main burner whereupon gas to the flash burners is turned otf and only a sustaining burner kept lit during the burning period of the main burner for maintaining the valve in position so that when the sustaining burner is extinguished by loss of gas, the main valve will quickly close for preventing subsequent ow of gas into the room from the main burner when the gas supply is re-established.

With these and other objects in view, my invention consists in the construction, arrangement and combination of the various parts of my gas burner control, whereby 'the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims and illustrated in the accompanying drawings, wherein:

Figure l is a diagrammatic showing of a gas burner control embodying my present invention, parts being in the non-operating position or Off Figure 2 is a similar diagrammatic view, the parts being in the position occurring right after the gas is turned on manually, the figure being designated Turned on. t

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Figure 2a is a fragmentary View of the central portion of Figure 2 taken at right angles to the Figure 2 showing.

Figure 3 is a similar diagrammatic view, with the parts in the Burning position which occurs after a short period following the Turned on position of Figure 2; and

Figure 4 is a similar diagrammatic view showing the l Turned off position wherein the gas valve has just been turned off manually and heated parts are not yet cooled back to the Off position of Figure 1.

On the accompanying drawings I have used the reference numeral 10 to indicate a gas supply line such as that for supplying domestic gas to gas ranges and ovens. A constantly burning pilot burner 12 is illustrated, this being the usual top pilot burner for lighting the top burners of the range.

A gas line 14 extends to a valve body 16 of the main valve shown generallyvat MV, this being a safety and operational sequence valve as will hereinafter appear. From the valve body 16, a gas line 18 goes to the main burner 20. A gas supply valve 22 is illustrated, this being the manual valve for turning on the gas supply for the oven or main burner 20. The gas supply valve 22 may be part of a temperature regulating valve for the oven as usually provided and is provided with a main burner passageway 27 which is normally in the position shown in Figure l, the valve 22 being Off as illustrated and indicated.

The valve body 16 is provided with a main valve seat 24 against which a main valve 26 is adapted to seat. The main valve 26 is carried by a diaphragm 28 and normally assumes the lowered position shown in Figure l due to its weight, gas pressure above the diaphragm 28 and a spring 29. The main valve 26 carries a standby valve seat 30 with which a standby valve 34 is normally engaged. A standby port 32 is provided in the main valve 26 and a standby gas line 33 bypasses gas from the gas supply line 10 directly to a pressure chamber of the valve body 16 above the diaphragm 28 through a standby bypass valve 35 which is adjustable for proper operation of the system.

The standby valve 34 is carried by a standby valve lever 36 pivoted at 38. This lever is normally in the lowered position with the valve 34 closed against the seat 30 and causing the valve 26 to also close against the seat 24 by a spring 40.

The valve 34 is adapted to be spaced from the valve seat 30 by a thermal power lever 42 pivoted at 44 which is actuated by a pin 50 extending from a diaphragm 48 of a power element consisting of the diaphragm 48 and a cup 46 in which it is enclosed. A capillary tube 52 connects with the cup 46 and extends from a temperature sensing bulb 54. The tube, bulb and power element are charged with a suitable actuating uid responsive to temperature such as mercury or the like so that when subjected to temperature, the diaphragm will be forced downwardly as will hereinafter appear. The valve 34 can also positively unseat the valve 26 relative to the seat 24 by means of a linger 31 extending upwardly from the valve 26 and having its upper end hooked over the valve 34 as at 37 (see Figure 2a).

The valve body 16 is provided with a flash burner valve seat 56 adjacent the bottom of the valve and a flash burner valve 58 is normally seated thereon by gravity, the valve being supported by a diaphragm 6). A bypass 62 is provided from the gas line 14 to the space in the valve body 16 below the diaphragm 60 and communicates gas to the valvexseat 56.

A flash and booster burner 66 and an intermediate flash burner 64 communicate with the bottom of the valve body 16 and receive gas from the by pass 62 when the valve 58 is open.

A first ash tube 68 is adapted to `receive gas .from Vthe ash burner 64 to propagate ame from the constantly burning pilot burner 12 to the ash burner 64 as in Figure 2 and a second ash tube 70 propagates ame from the intermediate ash burner 6ft to the flash and booster burner 66.

Adjacent the main or oven burner 20 is a pilot and sustaining burner 72 supplied with gas from a pilot burner passageway 74 in the gas supply valve 22 when turned to the On position as in Figure 2. After ame is propagated to vthe burner 66, it also lights the burner 72 which is close enough to the burner 66 to be thus lit. Both burners 66 and '72, it will be noted, are adjacent the temperature sensing bulb 54 for heating it and thereby operating the power element 46e48 as will hereinafter appear.

Practical operation In the Off phase of the operation as shown in Figure l, the constant gas source applied to the constantly burning pilot burner 12 keeps this burner lit and charges the pressure chamber of the main valve I6 above the diaphragm 28 with gas for subsequent operation of the valve. There is no gas flow through either of the valves 22 or MV.

To start the burner, the gas supply valve 22 is turned from the Off position of Figure l to the Turned on position of Figure 2 whereupon gas flows through the gas line 14 to the valve body 16 below the diaphragm 28 and through the bypass 62 into the chamber of the valve body 16 below the diaphragm 66. The pressure under the i diaphragm 60 opens the valve 56 with respect to the seat 56 so that gas then flows to the flash burners 64 and 66. They are thereupon ignited through the flash tubes 63 and 70 from the constantly burning pilot burner 12 as indicated by arrows a, b and c in the ash tubes. The bypass passageway 74 of the valve 22 also supplies gas to the pilot burner 72 and it is ignited from the ame issuing from the burner 66 as indicated by an arrow d across the temperature responsive bulb 54.

The bulb 54 is now being heated by both of the flames at the burners 66 and 72 which causes a quick acting or booster effect in that the use of two flames as compared with one hastens the action of the bulb in operating the power element 46-4S to open the standby valve 34 as in Figure 3. The opening of valve 34 relative to seat 30 results from the action of the diaphragm 48 responding to the build-up of pressure in the bulb 54 and the capillary tube S2 which lowers the pin 50, thereby swinging the thermal power lever 42 downwardly as in Figure 3 which results in swinging the lever 36 upwardly against the action of the spring 40. Since the gas pressure above the diaphragm 2? is thereby relieved through the standby port 32 (having a larger area than that through the bypass valve 35), the diaphragm is no longer able to hold the valve 26 against the seat 24 as in Figure 2 and the valve 34 is thereby opened with respect to the seat 30 as in Figure 3 so that the gas above the diaphragm 28 may pass through the standby port 32 in the main Valve 26 and the gas to the valve MV may flow through its seat 24 to the gas line i8 and the main burner where it is ignited from the flame of the pilot burner 72. If the valve 26 tends to stick to the seat 26, the valve 34 when it reaches the position shown in Figure 2a will positively unseat it whereupon the gas pressure from 14 under the diaphragm 28 may readily complete the opening of 26 as in Figure 3. This is the Burning phase as depicted in Figure 3.

In the burning phase the flash burners 64 and 66 are no longer needed and are extinguished by the pressure of the gas in the valve body 16 above the diaphragm 60 closing the valve 5S against the seat 56 as shown. The heat from the flash and sustaining burner '72 is sufficient to keep the lever 42 in the lowered position illustrated and since the flame at 66 is extinguished, the bulb 54 will not be heated as much and can thereby cool down more quickly during a subsequent safety operation. The condition .shown .in .Figure 3 will continue as long .as the oven or broiler is on (burner 20 burning) and the system does not interfere with the normal operation of the oven.

In the event of gas failure in the supply line Mi or failure due to clogged pipes or burner orifices, the main valve MV acts as a safety valve in that the bulb 54 will cool down because of the ame of the sustaining burner 72 going out and the parts of the valve will soon reassume the position shown in Figure l so that when the gas comes on again the condition will be the same as in Figure 2 except that there will be no fiame at the pilot burner 12 and consequently no flames at 64, 66 or '72. These pilot burners pass only a relatively small amount of gas which is not dangerous to be discharged into the room and serve to indicate to the user the failure of the gas supply. Thereupon the burner 12 may be relit and the system will function as intended.

Whenrthe burner is turned off, that is when the valve Z2 is turned from the On position of Figure 3 to the Off position of Figure 4, the gas pressure above the diaphragm 28 will close the main valve 26 as illustrated (as soon as the valve 34 returns sufficiently as in Figure 4 for the finger 31 and hook 37 to allow 26 to seat on 24) and thereafter there will be but a standby fiame indicated at 21 at the burner 20. This small flame is fed with gas through the standby port 32 until such time as the bulb 54 cools down and recloses the valve 34 against the seat 30 as in Figure l. The bulb 54 is far enough from it and from the burner 20 when burning full force so as not to be heated by either.

The purpose of the standby flame 2l is to re-ignite the burner in the event that the valve 22 is turned on again before the bulb 54 cools down to recycle the system as in Figure 2. The standby flame 21 continues to burn until all operational functions are completed which allows the main valve MV to be put back into fully automatic opration during the cooling cycle, the valve being ready for recycling at any time after the main burner standby iiame 21 has gone out.

In the event that the Valve 26 fails to seat as it should because of the flow of gas through the standby port 32, the valve 34 upon being lowered by the spring 4i) as the bulb 54 cools, will compress Vthe spring 29 and through it close the valve 26 before 34 seats at 30 to insure a period of standby fiame (21) before the bulb 54 has cooled sufiiciently for the return of the parts to the Figure 1 position for recycling. Thus all possible malfunctioning of the control is provided against so that the control operates in a safe manner under all conditions.

The control disclosed is so constructed as to eliminate any bleed openings found in many types of gas control valves which are always subject to clogging up and result in misoperation of the valve. It is also so designed as to eliminate adjustable linkages which must be properly set and must not change in their inter-relationships or an unsafe condition may exist. The valve disclosed performs the many functions as outlined and the valving and safety means are inter-related but are free of adjustments and malfunctions.

The pilot and sustaining burner 72 acts as a safety burner in that it sustains the heat for the bulb 54 in the burning position of the parts as in Figure 3, and in case it goes out it permits the main valve MV to close thus acting as a safety shut-down to prevent subsequent flow of gas through an open gas valve or main valve to the burner when the gas supply is rez-established. The main valve also serves as a safety when the gas supply vaive 22 is turned off causing the safety pilot 72 to cease to burn. Thereupon the bulb 54 cools off and during the cooling perioda flame Inustbe present for protection in case the valve 22 is turnedon again, which would pass unburned gas through the main burner. The standby flame 21 performs this function without the necessity of a separate standby pilot burner and continues to burn until the ,parts of themain valve .arein positionforre- 'aime 0 cycling (34 reseated on30 and 26 reseated on 24). Also during the cooling period the flash burner valve 58 remains closed because of gas pressure above the diaphragm 60 as in Figure 4 to prevent fiow of gas to the fiash burners 64 and 66 which are not needed as long as the standby fiame 21 is burning and until the main valve MV is in position for recycling.

Another important safety function is drop-out of the valve on low gas pressure. When the gas pressure approaches an unsatisfactory low for proper combustion at the burner, the bias of the spring 29 and the weight of the valve 26 will cause this valve to close, thus maintaining only the standby flame 21 and the sustaining flame at the burner 72 until such time as pressure either completely fails or rises again to reopen the valve 26.

Some changes may be made in the construction and arrangement of the parts of my gas burner control Without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

i claim as my invention:

l. A gas burner control of the character disclosed comprising in combination a safety and operational sequence valve having a valve body provided with an inlet first and second valve seats, a main outlet for said first seat and an auxiliary outlet for said second seat, a first valve closing element for said first valve seat, a second valve closing element for said second valve seat, first and second actuating diaphragms for said valve closing elements, the first diaphragm being responsive on one side to gas under pressure supplied to said valve and on the other side constantly responsive to the gas pressure in the supply line, said second diaphragm being responsive on one side to gas supplied to said valve and on the other side to gas flowing from the valve through said first valve seat, a main burner connected to said main outlet, a booster burner connected to said auxiliary outlet, said first valve closing element having a third valve seat, a third valve closing element normally seated thereon, temperature responsive means for unseating said third valve closing element with respect to said third valve seat, said temperature responsive means being responsive to a flame from said booster burner, said first valve closing element having a standby port for supplying gas to the main burner for maintaining a standby iiame thereat when said third valve closing element is open With respect to said third valve seat and said first valve closing element is closed with respect to said first valve seat, a pilot burner for the main burner, and a gas supply valve for supplying gas to said valve body and to said pilot burner, said temperature responsive means being also responsive to the flame from said pilot burner, and said booster and pilot burners being ignitible from a constantly burning pilot burner.

2. A gas burner control of the character disclosed comprising in combination a safety and operational sequence valve having a valve body provided with an inlet, first and second valve seats, a main outlet for said first seat and an auxiliary outlet for said second seat, a first valve closing element for said first valve seat, a second valve closing element for said second valve seat, first and second actuating diaphragms for said valve closing elements, the first diaphragm being responsive on one side to gas under pressure supplied to said valve and on the other side constantly responsive'to the gas pressure in the supply line, said second diaphragm being responsive on one side to gas supplied to said valve and on the other side to gas flowing from the valve through said first valve seat, a main burner connected to said main outlet, a fiash and booster burner for ignition from a constantly burning pilot burner, said flash and booster burner being connected to said auxiliary outlet, said first valve closing element having a third valve seat, a third valve closing element normally seated thereon, temperature responsive means for unseating said third valve closing element with respect to said third Vvalve seat, said temperature responsive means being responsive to a dame from said booster burner, said first valve closing element having a standby port for supplying gas to the main burner for maintaining a standby flame thereat when said third valve closing element is open with respect to said third valve seat and said first valve closing element is closed with respect to said first valve seat, a pilot and sustaining burner for ignition from a constantly burning pilot burner and adapted to light the main burner, and a gas supply valve for supplying gas to said valve body and to` said pilot and sustaining burner, said temperature responsive means being also responsive to the flame from said pilot and sustaining burner.

3. A gas burner control of the character disclosed comprising in combination a safety and operational sequence valve having a valve body provided with an inlet, first and second valve seats, a main outlet for said first seat and an auxiliary outlet for said second seat, a first valve closing element for said first valve seat, a second valve closing element for said second valve seat, first and second actuating diaphragms for said valve closing elements, the first diaphragm being responsive on one side to gas under pressure supplied to said valve and on the other side constantly responsive to the gas pressure in the supply line, said second diaphragm being responsive on one side to gas supplied to said valve and on the other side to gas flowing from the valve through said first valve i seat, a main burner connected to said main outlet, a

Ybooster burner connected to said auxiliary outlet, said first valve closing element having a third valve seat, a third valve closing element normally seated thereon, temperature responsive means for unseating said third valve closing element with respect to said third valve seat, said temperature responsive means being responsive to a fiarne from said booster burner, said first valve closing element having a standby port for supplying gas to the main burner for maintaining a standby flame thereat when said third valve closing element is open with respect to said third valve seat and said first valve closing element is closed with respect to said first valve seat, a pilot burner for the main burner supplied with gas when said inlet is supplied With gas, said temperature responsive means being also responsive to the flame from said pilot burner, and fiash tube means extending from said booster and pilot burners to a constantly burning pilot burner.

4. A gas burner control of the character disclosed comprising in combination a safety and operational sequence valve having a valve body provided with an inlet, first and second valve seats, a main outlet for said rst seat and an auxiliary outlet for said second seat, a first valve closing element for said first valve seat, a second valve closing element for said second valve seat, first and second actuating diaphragms for said valve closing elements, the first diaphragm being responsive on one side to gas under pressure supplied to said valve and on the other side constantly responsive to the gas pressure in the supply line, said second diaphragm being responsive on one side to gas supplied to said valve and on the other side to gas flowing from the valve through said first valve seat, a main burner connected to said main outlet, a booster burner and an intermediate flash burner connected to said auxiliary outlet, said first valve closing element having a third valve seat, a third valve closing element normally seated thereon, temperature responsive means for unseating said third valve closing element with respect to said third valve seat, said temperature responsive means being responsive to a arne from said booster burner, said first valve closing element having a standby port for supplying gas to the main burner for maintaining a standby fiarne thereat when said third valve closing element is open with respect to said third valve seat and said first valve closing element is closed with respect to said first valve seat, a pilot burner for the main burner, and a gassupply valve for supplying gas to said valve body and to said pilot burner, said temperature responsive means being also responsive to the flame from said pilot burner, and flash tube means for igniting said intermediate flash burner from a constantly burning pilot burner and said booster burner from said intermediate flash burner, said pilot burner being ignitible from said booster burner.

5. In a gas -burner control, a safety and operational sequence valve for a main burner, a piiot burner, a booster burner, and a gas supply valve comprising a valve body having an inlet chamber, an outlet chamber, a pressure chamber and a bypass chamber, a first diaphragm separating said inlet chamber from said pressure charnber, a second diaphragm separating said outlet chamber from said bypass chamber, said valve body having a first valve seat between said inlet chamber and said outlet chamber and a second valve seat through which gas fiows from said bypass chamber, a first valve closing element carried by said first diaphragm for said 'irst valve seat, a second valve closing element carried by said second diaphragm for said second valve seat, said first valve closing element having a standby port therethrough, said first valve closing element having a seat carried thereby for said standby port, a third valve closing element for said third valve seat, temperature responsive means for opening said third valve closing element relative to said third valve seat in response to a relatively high temperature, said temperature responsive element when cold closing said third valve closing element relative to said third valve seat and said first valve closing element relative to said iirst valve seat, said booster burner being connected to receive gas from said second valve seat, said pilot burner being adapted to receive gas whenever said inlet chamber receives gas, said booster and pilot burners being eiiective to heat said temperature responsive element to cause operation thereof for opening said third valve closing element relative to said third valve seat.

6. A gas burner control of the kind disclosed comprising a safety and operational sequence valve for a main burner, a pilot and sustaining burner, a liash and booster burner, and a gas supply valve comprising a valve body having an inlet chamber, an outlet chamben, a pressure chamber and a bypass chamber, a first diaphragm separating said inlet chamber from said pressure chamber, a second diaphragm separating said outlet chamber from said bypass chamber, said valve body having a first valve seat between said inlet chamber and said outlet chamber and a second valve seat through which gas liows from said bypass chamber, a first valve closing element carried by said first diaphragm for said first valve seat, a second valve closing element carried by said second diaphragm for said second valve seat, said first valve closing element having a standby port therethrough, said first valve closing clement having a seat carried thereby for said standby port, a third valve closing element for said third valve seat, temperature responsive means for opening said third valve closing element relative to said third valve seat in response to a relatively high temperature, said temperature responsive element when cold closing said third valve closing element relative to said third valve seat and said first valve closing element relative to said first valve seat, said ash and booster burner being connected to receive gas from said second valve seat, said pilot and sustaining burner being adapted to receive gas whenever said inlet chamber receives gas, said tiash and booster' burner and said pilot and sustaining burner being effective to heat said temperature responsive element to cause operation thereof, and said pilot and sustaining burner being operable to retain said temperature responsive element in its operative position.

7. ln a burner control of the ciass wherein there is a main burner and a constantly burning pilot burner, pilot burner means for lighting said main burner, a fuel supply line for `supplying fuel to said main burner and to said p'ilot burner means, a safety shut-ott valve in the fuel supply line for the main burner and normally in closed position to shut oi the supply of fuel to said main burner, booster burner means, valve means in the fuel snppiy line for said booster burner means and operable to closed position when said safety shut-oi valve in the fuel supply line for the main burner is opened whereby to shut ofi the supply of fuel to said booster burner means, standby means for relighting said main burner when the safety shut-off valve in the fuel supply line to the main burner is in closed position and the valve means in the fuel supply line for said booster burner is also closed, the safety shut-off valve having port means through which a limited amount of fuel is delivered to the main burner to maintain a small dame thereat to constitute said standby means, and temperature responsive means responding to heat from said pilot burner means and said booster burner means to open said port means and said safety shut-01T valve in response to a relatively high temperature and to close said port means in response to a low temperature.

8. For use in a gas range having a gas supply, a constantly burning pilot light and an oven burner remote from the constantly burning pilot light, the combination of an voven pilot burner and an auxiliary pilot burner for said oven burner, means including iiash tubes and an intermediate pilot burner for igniting said oven and auxiliary pilot burners from said constantly burning pilot light, an automatic valve means for the oven burner hav- :ing a main valve and a standby port bypassing the main valve to furnish reduced gas to the oven burner, manually controlled valve means, a first conduit including said manually controlled valve means adapted to interconnect the gas supply and said oven pilot burner, a second conduit including said manually controlled valve means and said automatic valve means in series adapted to interconnect the gas supply and said oven burner, a third conduit between the inlet side of said automatic valve means and said auxiliary and intermediate pilot burners, means responsive to pressure controlled by opening and closing of the main valve to `open or close the third conduit, said manually controlied valve means in closed and opened positions simultaneously closing ori or opening, respectively, said conduits and said main valve means having pressure responsive operating means controlled by control means responsive to heat generated by said oven pilot burner to open said valve when said control means is above a predetermined temperature, and means operated solely by said control means to control the standby port, the cycle of operation for lighting said oven burner requiring movement of said manually controlled valve means to its on position whereby gas is supplied from the inlet side of the automatic valve means to said intermediate and auxiliary pilot burners and from the source of gas to said oven pilot burner, said pilot burners being then lit from said constantly burning pilot light, said oven piiot burner then heating the control means of the automatic valve means above the predetermined temperature to cause said automatic valve means to open said standby port and to operate the pressure responsive operating means to open the main valve whereby gas is supplied to the oven burner and is there ignited by said oven pilot burner and said operating means closes off the fiow of gas through said third conduit, and the cycle of operation for closing oi said oven burner requiring only a movement of the manually controlled valve to oit position whereby the flow of gas to said automatic valve means and to said oven pilot burner is immediately shut off, said oven burner remaining lit on low larne through said standby port until the control means for the automatic valve means has been cooled below said predetermined temperature whereupon the standby port of said `automatic valve means closes to extinguish the standby flame and condition the automatic valve means for recycling.

9. The combination of claim 8 wherein the control means for the automatic valve means is positioned to be also responsive to the heat generated by said auxiliary pilot burner.

10. A gas burner control of the character disclosed comprising a main burner, a gas supply conduit connected to the main burner, a sustaining pilot burner adjacent to the main burner, a booster pilot burner adjacent to the sustaining pilot burner and the main burner, a shut ofi valve and an automatic control valve in series in the supply conduit, a connection from the shut off valve to the sustaining pilot burner to supply fuel thereto when the shut off valve is open, a connection from the automatic valve to the booster pilot burner, an auxiliaryI valve and a main valve inthe automatic valve controlling the supply of fuel to the booster pilot burner and the main burner respectively, means controlled by fuel pressure supplied to the automatic valve when the shut otf valve is open to open the auxiliary valve, pressure responsive means responsive to the difference in pressure between the inlet side of the main valve and a point anterior to the shut oit valve to operate the main valve, a by-pass through the main valve connecting said point to the main burner, a closure for the by-pass, and heat re sponsive means heated by the ash and booster pilot burners operable when cool to move the closure onto the by-pass and to close the main valve and when heated to move the closure away from the by-pass and allow the main valve to open.

l1. A gas burner control comprising a main burner, a pilot burner, a gas supply conduit connected to the main burner to supply gas thereto, a ymain valve in the conduit to control the supply of gas to the main burner, a connection from the supply conduit anterior to the main valve to the pilot burner, an auxiliary valve in the connection, pressure responsive means responsive to the difference in pressure in the connection and in the supply conduit posterior to the main valve to open the auxiliary valve when the main valve is closed and to close the auxiliary valve when the main valve is open, a bypass aroundthe main valve to supply a minimum amount of fuel to the main burner when the main valve is closed, a control valve for the bypass, temperature responsive means heated by the pilot burner to open the control valve and the main valve in response to a predetermined temperature, and means separate from the temperature responsive means to close the main valve without affecting the control valve, the temperature responsive means closing the control valve when it cools below said predetermined temperature.

References Cited in the tile of this patent UNITED STATES PATENTS 2,506,403 Witzel May 2, 1950 2,512,173 Ray June 20, 1950 2,557,927 Abrams June 26, 1951 2,588,137 Marvin Mar. 4, 1952 

